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FDA: Sunscreen Chemicals in Blood Show Need for Safety Testing

By Bara VaidaMay 13, 2019

Just as summer is about to begin, the FDA has published a study raising questions about the safety of many of the chemicals used in common sunscreens.

The FDA-funded study, published this month found that bloodstream levels of some sunscreen ingredients -- including avobenzone and oxybenzone — were absorbed into the bodies of sunscreen study participants at potentially toxic levels. In some animal studies, oxybenzone has been shown to disrupt hormone patterns.

FDA officials emphasized that they’re not saying sunscreen ingredients are unsafe. Rather, the agency is seeking more testing. It still recommends that consumers use sunscreen because of the damaging effect of prolonged sunlight on unprotected skin. The agency also said two sunscreen ingredients - zinc oxide and titanium dioxide - are safe.

The study follows on the agency’s February 2019 proposed rule to update regulations on sunscreens. In that proposal, the agency said two sunscreen ingredients -- zinc oxide and titanium dioxide -- are safe and requested more information about the safety data of 12 other sunscreen ingredients.

Study co-authors Theresa M. Michele, MD, director of the FDA’s Center for Drug Evaluation and Research’s division of nonprescription drug products and new drugs office, and David Strauss, MD, director of the FDA’s division of applied regulatory science explain their research and what it means for consumers.

WebMD: Why did the FDA decide to test sunscreen chemicals now?

Strauss: Sunscreens have been available over the counter for a long time now but the science has evolved over the years. It was previously thought…that sunscreens were not absorbed, but with the evolving science being able to detect lower levels of ingredients in the blood, we have been requesting data [from industry] on the systemic absorption of sunscreen ingredients. There was some question from industry about how to do these studies, so we sought to do a pilot study … to really lay out the framework of how to perform these studies and to gather some initial data.

WebMD: How long has FDA been requesting this? Was industry pushing back to not want to do this?

Michele: We have been evaluating sunscreens now since the early 1970s. It used to be that people occasionally used them …. Now, we are telling people to use these products on a daily basis and to reapply frequently … due to the fact that they have been demonstrated to prevent skin cancer. Back in 2014 …we proposed testing absorption of these ingredients and new ingredients that manufacturers were proposing to put on the market. We were requesting the data for new ingredients in 2014 and 2015, but manufacturers have yet to submit any of those data. We asked for data on existing ingredients in the February 2019 rule. This [study] was part of the response to try to help manufacturers to do these studies and give them a bit more guidance on that.

WebMD: Why didn’t the FDA test for these ingredients before?

Michele: It’s not really FDA’s job to test ingredients. That isn’t what we do. We have a very teeny, tiny research budget. It’s up to industry to provide the data and it is our job as regulators to look at the data and try to figure out what it means for consumers. In this case, we felt these data were important and that we [were] going to use our tiny, teeny research budget to try to take the initial steps necessary to formally evaluate these ingredients.

WebMD: Up until now, these ingredients have been considered effective and safe. Was there some other testing process that they went through before now?

Michele: Yes. The initial analyses were done in the 1970s, and then over the years we updated it. The last time the ingredients themselves were looked at was in 1999. And a lot has changed since 1999.

WebMD: The study states that “these results do not indicate that individuals should refrain from the use of sunscreen.” Why not, if we’re not sure they don’t cause harm?

Michele: Right now, we know that sunscreens have significant benefit in terms of prevention of skin cancer and other UV damage. We also, based on this study, have data showing that certain sunscreen ingredients are absorbed, which means that they go into the body. But just because something is absorbed, doesn’t mean that it is unsafe. What it means is that we need further testing. And given that we know that there are benefits and we don’t know, for sure, that there are any harms, we still strongly recommend that people continue to use their sunscreens while these data are being gathered.

WebMD: If we don’t know for sure that there aren’t any harms, shouldn’t consumers switch to using sunscreens with the two ingredients that are considered safe -- zinc oxide and titanium oxide.

Michele: [With] those two ingredients, zinc oxide and titanium oxide, we have not asked for any additional data. We believe we have sufficient data. Certainly, if someone were particularly concerned, they could use sunscreens using those ingredients. But again, we aren’t recommending that people don’t use sunscreens. Quite the opposite ... use your sunscreen.

WebMD: Among the 12 sunscreen ingredients that the FDA says need more information to determine if they are generally recognized as safe and effective, are there any that have more concerning evidence to date?

Michele: A lot of them just have just very little data. We have laid this out in our proposed rule [in February]. We do have a bit more data on oxybenzone and we are also looking for additional data on that, at this time. But again, we aren’t saying that you shouldn’t be using any particular ingredient or warning [anyone] away from a particular ingredient. We are just asking for additional data.

WebMD: What advice do you have for people who are concerned about sunscreen chemicals?

Michele: I recommend that people continue to use their sunscreen in conjunction with their other sun protection measures. If they are absolutely adamant they can’t, then I suggest they use zinc and titanium and… other sun protection measures are key. Stay out of the sun between the peak hours of 10 [a.m. ] and 2 [p.m.], seek shade, wear protective clothing, wear sunglasses, wear hats. Skin cancer rates are rising and we don’t want to do anything that would discourage consumers from protecting themselves from the effects of the sun. And of course, stay away from tanning beds.

WebMD: Are “natural” or organic sunscreens better for you?

Michele: The FDA doesn’t regulate the term ‘natural’ or ‘organic’, in terms of having a regulation that defines the term. So, I have no idea what they mean.

We can’t say if they would be safer or not safer. … If I were a consumer, I’d say that term means nothing.

WebMD: Would you use one of the commercial sunscreens on your kids or on yourself this summer that includes one of those 12 ingredients of concern?

Michele: Yes. I have them in my daughter’s pool bag now. Swim team starts in a week.

WebMD: What is the next step in finding out more about the health effects of the chemicals in sunscreens?

Michele: I think the next step for manufacturers will be, they need to do a more definitive absorption study because as what David noted, we did just a pilot study and they need to do more long-term animal testing to see what happens to these ingredients once they are in the body.

WebMD: When will manufacturers get back to you on their next step in testing these ingredients?

Michele: The comment period for the proposed rule-making closes at the end of June, so we expect to hear back from manufacturers within that period of time as to what ingredients they intend to perform testing on.

WebMD: Should the FDA be doing its analysis of the chemicals instead of allowing the companies, whose financial interests are at stake, to provide the data themselves?

Michele: The way the FDA works is that industry is responsible for doing the studies but they have to do them under very specific conditions that are defined by the FDA. In the case of sunscreens, these data will be available to the public, to review if they choose to do so, but unlike other regulatory agencies…we actually look at the real data and analyze it ourselves. We just aren’t the people that are running the study.

WebMD: Will the companies' own analyses be made public?

Michele: If you look at our proposed rule, all of the data in there, everything is available in the public domain.

WebMD: How will the FDA decide whether the analyses provided by the sunscreen makers meets the standard of generally recognized as safe and effective?

Michele: That is what the FDA does. We do a benefit risk analysis for every drug we review and every ingredient… to basically determine whether the benefits outweigh the risks.

WebMD: How long will it be before we have more conclusive data about the safety question?

Michele: These data [take] some time to develop and we intend to work with manufactures to help them get this along as quickly as possible to ensure that consumers continue to have access to safe and effective sunscreen.

WebMD: Will we know by next summer?

Michele: Well, some of the carcinogenicity toxicology studies take about 3 years to do.

Clarification: The FDA clarified that it was seeking data on new ingredients in 2014 and 2015 and that it asked for data on existing ingredients in the 2019 rule.

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